When public health officials announced early last month that, in four days, they would begin spraying Sacramento neighborhoods to kill mosquitoes that carry West Nile virus, local news reporters turned to UC Davis for expert opinions.
The barrage of questions began with the basics: What were "pyrethrins" and were they safe? Was the West Nile virus infection serious enough to justify laying a mist of pesticide over 70,000 acres of neighborhoods? Once spraying began in Sacramento, the inquiries shifted: Were people reporting illness from the spray? Had non-target insects and animals been harmed? Was spraying being recommended for neighboring communities, such as Davis?
And then in mid-August, officials said it might be necessary to spray in Davis, too. The barrage of questions began again.
Spraying risks
UC Davis experts rose to the occasion, as they have in other public-health crises, such as the mad-cow case of 2003. In the first major newspaper story, in the Aug. 5 Sacramento Bee, toxicologist and pesticide expert Bruce Hammock emphasized the safety of pyrethrins, which are insecticides derived from chrysanthemum flowers. "Nothing is innocuous, but this is about as innocuous as you can get," he said.
On KCRA-TV's news the afternoon before Sacramento spraying began, entomologist Rick Roush repeated that message to viewers of Sacramento's Channel 3, saying, "The risks of the spray are minuscule compared to the risk of getting West Nile virus."
Early on two post-spray mornings, Michael Parrella drove to the Sacramento studio of UPN Channel 58's "Good Day Sacramento" for live interviews. Parrella is an expert in integrated pest management and associate dean for agricultural sciences in the College of Agricultural and Environmental Sciences. He carefully documented the factors that justified spraying. "Everything is pointing toward an epidemic and we want to prevent that from happening," he said.
Walter Boyce, a veterinarian and co-director of the School of Veterinary Medicine's Wildlife Health Center, studied the effects of spraying on non-target organisms, such as earwigs and crickets. His preliminary results were reported in the Sacramento Bee and Davis Enterprise, and in the Sacramento and San Francisco areas on PBS' KQED-FM radio – unconventional publication forums for scientists but a valuable service to worried people. The exposed creatures, Boyce said, survived just as well as those protected from the spray.
Boyce's studies of the effects of West Nile virus on wild bird populations, with Holly Ernest, director of the vet school's Wildlife Genetics Lab, were described by KOVR-13 and KPIX-5, the CBS news affiliate stations, respectively, in Sacramento and San Francisco.
Wide range of faculty
Other UC Davis faculty and staff members who helped reporters tell the West Nile story included: Arthur Craigmill, toxicologist; Alison Kent, Wildlife Health Center editor; Grace Lee, field biologist; Stephen McCurdy, an expert on pesticides and farmworker hazards; Bill Reisen, a research entomologist at the Center for Vector-Borne Diseases; Christian Sandrock, assistant professor of clinical medicine; Tom Scott, a UC Davis entomologist; Ron Tjeerdema, environmental toxicologist; Richard Tucker, professor of cell biology; and Tom Zavortink, a researcher at the UC Davis Bohart Museum of Entomology.
To see news reports that included UC Davis references, visit www.news.ucdavis.edu/in_the_news and search for "Nile."